Pivotally mounted current collecting contact shoe assembly

ABSTRACT

A current collecting contact shoe assembly comprising a plurality of closely spaced contact shoes pivotally mounted on imbricating support arms so as to permit substantial wear of the contact surface of the contact shoes under increasing contact surface condition.

United States Patent Charamel Apr. 30, 1974 PIVOTALLY MOUNTED CURRENT [56] References Cited COLLECTING CONTACT SHOE ASSEMBLY I UNITED STATES PATENTS [75] Inventor: Pierre Charamel, Les Cotes De 2,325,971 8/1943 Newbrough 191/59.l Sassenage France Ventre i 3,405,240 10/1968 Kilburg 191/45 R Assignee: Merlin Gerin, Societe y 1,821,425 9/1931 Coseo 191/58 Grenoble, France Primary ExaminerGera1d M. Forlenza [22] Flled' 1972 Assistant Examiner-D. W. Keen [21] Appl. No.: 217,199 Attorney, Agent, or Firm-Stevens, Davis, Miller &

. Mosher 1 [30] Foreign Application Priority Data ABSTRACT Jan. 22, 1971 France 71.02908 A current collectmg contact shoe assembly comprlsmg [52] US CL I i 191/49 191/58 a plurality of closely spaced contact shoes pivotally [51] Int. Cl 3 5/38 mounted on imbric ating support arms so as to permit [58] Field 49 50 substantial wear of the contact surface of the contact shoes under increasing contact surface condition.

4 Claims, 2 Drawing Figures PIVOTALLY MOUNTED CURRENT COLLECTING CONTACT SHOE ASSEMBLY This invention relates to pivotally mounted current collecting contact shoe assemblies cooperating with a current distributing conductor rail.

In known movable multiple contact shoe assemblies, the contact shoes are individually slidably mounted in guide channels which are secured to a movable support structure whereby spring members urge the shoes against the contact rail. The part of the contact shoe engaged in the guide channel must be sufficiently long to maintain and guide the shoe without the risk of the latter jamming.

It is an object of the invention to provide a current collecting device of simple, compact and low-cost construction having an improved mechanical behavior particularly with regard to:

capability of instantaneously following all imperfections of the contact surface of the feed conductor;

absence of risk of jamming;

reduction of detrimental vibrations;

reduction of friction.

It is another object of the invention to provide a compact and reliable current collecting device permitting optimum utilization of the contact shoe volume under high speed, that is high wear conditions, so as to limit the frequency of replacement of worn-down contact shoes.

Still another object of the invention is to provide a current collecting contact shoe assembly having an increased contact surface as the wear of the contact shoes progresses and, as a consequence, the application force of the bias springs diminishes.

These and other advantages and characteristics of the invention will become apparent from the following description of one embodiment of the invention which has been shown in the accompanying drawing, in which:

FIG. 1 is a partial view in sectional elevation of a current collecting device in accordance with the invention;

FIG. 2 is a plan view of the device of FIG. 1 in which only two contact shoes have been shown, only one being shown with its contact spring.

In the figures, a rail-shaped feed conductor for the supplying of current extends along the path of travel of a movable support structure or frame 12 only a part of the outer portion of which facing the rail 10 is shown in the figures. The frame 12 carries a number of current collecting members in the form of contact shoes or brushes 14, 16, 18, etc. which cooperate with the rail 10. The contact shoes 14, 16, 18, etc. are staggered and aligned along the rail 10, a small free space being provided between the adjacent contact shoes for reasons which will become more evident from the following description.

The contact shoes 14, 16, 18 being all of the same shape and their system of attachment being identical, only one of them, 14, will be described. The brush or shoe 14 consists of a parallelepiped block of copper or alloy of copper and graphite, one of the faces 19 of which is advantageously cut in a dihedral shape so as to fit in a mating contact surface 21 of the rail 10, the opposite face being fastened to abrush holding or support arm 22 which extends substantially in the longitudinal direction of the frame 12. The end 24 of the arm 22 bearing the brush l4 fits in a recess 26 provided in the brush 14, the attachment being advantageously effected by brazing or welding. The opposite end 28 of the arm 22 terminates in a sleeve 30 which is pivotally mounted on a pivot axis 32 rigidly connected with the moving part 12. Over the sleeve 30 there is placed a coil spring 34 of the clothespin type secured at the one end to the moving part 12 and at the other end to the arm 22 so as to urge the latter in clockwise direction as seen in FIG. 1 so as to apply the brush 14 against the feed rail 10.

The support structure 12 has a groove 36 opposite the rail 10, within which groove there are arranged, staggered apart, the sleeves 30 of the arms 22 of the different successive brushes l4, 16, 18. The pivot axes 32 of the brushes 14, 16, 18 are shifted forward with respect to the direction of displacement of the moving part 12, indicated by the arrow in FIG. 1, so as to exert a tractive force on the brushes supported, whereby the pivot axis 32 of the support arm of each contact shoe is positioned above the central part of the preceding contact shoe. The offset and the bent shape of the arms 22 permits an overlapping or imbrication of the support arms 22. The space between the brushes 14, l6, 18 can thus be reduced to a maximum so as to present a practically continuous contact surface over the entire length of the brushholder. It is nevertheless neccessary to provide a space d between the successive brushes so as to permit pivoting around the axes 32 during the wear of the brushes.

The operation of the current collecting device in accordance with the invention is obvious:

Upon the displacement of the structure 12 along the rail 10, the brushes 14, 16, 18 are carried along by their pivot axes 32 and the associated arms 22 which apply a tractive force in the direction of displacement to them. The springs 34 urge the brushes into contact with the rail 10, the current picked up being transmitted by the brushes and the arms 22 via flexible conductors or braids (not shown). At the start, and as long as the brusher are not worn, the opposite side faces of the prismatic brushes are substantially parallel and slight imperfections in the rail 10 are compensated for by a slight pivoting of the brush upon coming into contact with said imperfection. The wear of the brushes 14, 16, 18 is compensated for by a pivoting of the brush/arm assembly around the axis 32 so as to assume an inclined position, shown in discontinuous lines in FIG. 1. It is easy to see that this pivoting is accompanied by an increase in the contact surface between the brush and the rail 10, the space d between the successive brushes being reduced as a result. The increase in surface can compensate for the decrease in contact pressure resulting from the elongation, or more precisely the decrease in torsion of the spring 34 resulting from the pivoting of the arm 22.

It is easy to see that the brushes 14 to 18 become worn more and more diagonally and that the volume thereof can be utilized practically completely, their guiding being preserved in full until they are completely worn out. The replacement of the brushes is effected in a particularly simple manner by removing the axis 32 and inserting a new brush-supporting arm assembly. The resistance to pivoting at the pivot axes 32 can be maintained extremely small by lubrication or the use of suitable anti-friction materials.

What is claimed is:

l. A current collecting assembly for use with a longitudinally extending current distribution conductor rail comprising an elongated support structure carrying a plurality of coplanar parallel pivot axes extending substantially perpendicularly to the longitudinal direction of said support structure and spaced apart in said direction, a plurality of contact shoe support arms having one end portion pivotally mounted on said pivot axes, respectively, the opposed end portion of each support arm carrying a contact shoe of conductive material having a general prismatic shape, and resilient bias means urging said contact shoes away from said support structure, said contact shoes being closely spaced apart in said direction, the pivotally mounted end portions of said support arms extending in the same direction in such a manner that the support arms are in imbricated relation.

2. An assembly as set forth in claim 1, said pivot axes, said support arms and said contact shoes being shaped and positioned in such a manner that said contact shoes in substantially diagonally worn condition are in imbricated relation.

3. An assembly as set forth in claim 1, all support arms and all contact shoes being the same shape, the pivot axis of all but the first contact shoe being positioned above the central portion of the preceding contact shoe.

4. A current collecting assembly for use with a longitudinally extending current distribution conductor rail, comprising a longitudinally extending support structure carrying a plurality of coplanar parallel pivot axes extending perpendicularly to the longitudinal direction of said support structure and which are regularly spaced in said direction, a plurality of similarly shaped contact shoe support arms having one end portion pivotally mounted on said pivot axes, respectively, the opposed end portion carrying a contact shoe of conductive material, and resilient bias means urging said contact shoes away from said support structure, the length of the gap between confronting end portions of adjacent contact shoes being small with respect to the pitch of said pivot axes, the pivotally mounted end portions of said support arrns extending in the same direction in such a manner that the support arms of all but the first contact shoe overlap a substantial longitudinal portion of the preceding contact shoe. =l= 

1. A current collecting assembly for use with a longitudinally extending current distribution conductor rail comprising an elongated support structure carrying a plurality of coplanar parallel pivot axes extending substantially perpendicularly to the longitudinal direction of said support structure and spaced apart in said direction, a plurality of contact shoe support arms having one end portion pivotally mounted on said pivot axes, respectively, the opposed end portion of each support arm carrying a contact shoe Of conductive material having a general prismatic shape, and resilient bias means urging said contact shoes away from said support structure, said contact shoes being closely spaced apart in said direction, the pivotally mounted end portions of said support arms extending in the same direction in such a manner that the support arms are in imbricated relation.
 2. An assembly as set forth in claim 1, said pivot axes, said support arms and said contact shoes being shaped and positioned in such a manner that said contact shoes in substantially diagonally worn condition are in imbricated relation.
 3. An assembly as set forth in claim 1, all support arms and all contact shoes being the same shape, the pivot axis of all but the first contact shoe being positioned above the central portion of the preceding contact shoe.
 4. A current collecting assembly for use with a longitudinally extending current distribution conductor rail, comprising a longitudinally extending support structure carrying a plurality of coplanar parallel pivot axes extending perpendicularly to the longitudinal direction of said support structure and which are regularly spaced in said direction, a plurality of similarly shaped contact shoe support arms having one end portion pivotally mounted on said pivot axes, respectively, the opposed end portion carrying a contact shoe of conductive material, and resilient bias means urging said contact shoes away from said support structure, the length of the gap between confronting end portions of adjacent contact shoes being small with respect to the pitch of said pivot axes, the pivotally mounted end portions of said support arms extending in the same direction in such a manner that the support arms of all but the first contact shoe overlap a substantial longitudinal portion of the preceding contact shoe. 